Geometry Nodes: fields and anonymous attributes

This implements the initial core framework for fields and anonymous
attributes (also see T91274).

The new functionality is hidden behind the "Geometry Nodes Fields"
feature flag. When enabled in the user preferences, the following
new nodes become available: `Position`, `Index`, `Normal`,
`Set Position` and `Attribute Capture`.

Socket inspection has not been updated to work with fields yet.

Besides these changes at the user level, this patch contains the
ground work for:
* building and evaluating fields at run-time (`FN_fields.hh`) and
* creating and accessing anonymous attributes on geometry
  (`BKE_anonymous_attribute.h`).

For evaluating fields we use a new so called multi-function procedure
(`FN_multi_function_procedure.hh`). It allows composing multi-functions
in arbitrary ways and supports efficient evaluation as is required by
fields. See `FN_multi_function_procedure.hh` for more details on how
this evaluation mechanism can be used.

A new `AttributeIDRef` has been added which allows handling named
and anonymous attributes in the same way in many places.

Hans and I worked on this patch together.

Differential Revision: https://developer.blender.org/D12414

9 files changed, 527 insertions, 203 deletions

diff --git a/source/blender/blenkernel/intern/anonymous_attribute.cc b/source/blender/blenkernel/intern/anonymous_attribute.cc
new file mode 100644
index 00000000000..67611053d83
--- /dev/null
+++ b/source/blender/blenkernel/intern/anonymous_attribute.cc
@@ -0,0 +1,118 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include "BKE_anonymous_attribute.hh"
+
+using namespace blender::bke;
+
+/**
+ * A struct that identifies an attribute. It's lifetime is managed by an atomic reference count.
+ *
+ * Additionally, this struct can be strongly or weakly owned. The difference is that strong
+ * ownership means that attributes with this id will be kept around. Weak ownership just makes sure
+ * that the struct itself stays alive, but corresponding attributes might still be removed
+ * automatically.
+ */
+struct AnonymousAttributeID {
+  /**
+   * Total number of references to this attribute id. Once this reaches zero, the struct can be
+   * freed. This includes strong and weak references.
+   */
+  mutable std::atomic<int> refcount_tot = 0;
+
+  /**
+   * Number of strong references to this attribute id. When this is zero, the corresponding
+   * attributes can be removed from geometries automatically.
+   */
+  mutable std::atomic<int> refcount_strong = 0;
+
+  /**
+   * Only used to identify this struct in a debugging session.
+   */
+  std::string debug_name;
+
+  /**
+   * Unique name of the this attribute id during the current session.
+   */
+  std::string internal_name;
+};
+
+/** Every time this function is called, it outputs a different name. */
+static std::string get_new_internal_name()
+{
+  static std::atomic<int> index = 0;
+  const int next_index = index.fetch_add(1);
+  return "anonymous_attribute_" + std::to_string(next_index);
+}
+
+AnonymousAttributeID *BKE_anonymous_attribute_id_new_weak(const char *debug_name)
+{
+  AnonymousAttributeID *anonymous_id = new AnonymousAttributeID();
+  anonymous_id->debug_name = debug_name;
+  anonymous_id->internal_name = get_new_internal_name();
+  anonymous_id->refcount_tot.store(1);
+  return anonymous_id;
+}
+
+AnonymousAttributeID *BKE_anonymous_attribute_id_new_strong(const char *debug_name)
+{
+  AnonymousAttributeID *anonymous_id = new AnonymousAttributeID();
+  anonymous_id->debug_name = debug_name;
+  anonymous_id->internal_name = get_new_internal_name();
+  anonymous_id->refcount_tot.store(1);
+  anonymous_id->refcount_strong.store(1);
+  return anonymous_id;
+}
+
+bool BKE_anonymous_attribute_id_has_strong_references(const AnonymousAttributeID *anonymous_id)
+{
+  return anonymous_id->refcount_strong.load() >= 1;
+}
+
+void BKE_anonymous_attribute_id_increment_weak(const AnonymousAttributeID *anonymous_id)
+{
+  anonymous_id->refcount_tot.fetch_add(1);
+}
+
+void BKE_anonymous_attribute_id_increment_strong(const AnonymousAttributeID *anonymous_id)
+{
+  anonymous_id->refcount_tot.fetch_add(1);
+  anonymous_id->refcount_strong.fetch_add(1);
+}
+
+void BKE_anonymous_attribute_id_decrement_weak(const AnonymousAttributeID *anonymous_id)
+{
+  const int new_refcount = anonymous_id->refcount_tot.fetch_sub(1) - 1;
+  if (new_refcount == 0) {
+    delete anonymous_id;
+  }
+}
+
+void BKE_anonymous_attribute_id_decrement_strong(const AnonymousAttributeID *anonymous_id)
+{
+  anonymous_id->refcount_strong.fetch_sub(1);
+  BKE_anonymous_attribute_id_decrement_weak(anonymous_id);
+}
+
+const char *BKE_anonymous_attribute_id_debug_name(const AnonymousAttributeID *anonymous_id)
+{
+  return anonymous_id->debug_name.c_str();
+}
+
+const char *BKE_anonymous_attribute_id_internal_name(const AnonymousAttributeID *anonymous_id)
+{
+  return anonymous_id->internal_name.c_str();
+}
diff --git a/source/blender/blenkernel/intern/attribute_access.cc b/source/blender/blenkernel/intern/attribute_access.cc
index aa0af294bc3..08bd5dc5981 100644
--- a/source/blender/blenkernel/intern/attribute_access.cc
+++ b/source/blender/blenkernel/intern/attribute_access.cc
@@ -44,6 +44,8 @@ using blender::float3;
 using blender::Set;
 using blender::StringRef;
 using blender::StringRefNull;
+using blender::bke::AttributeIDRef;
+using blender::bke::OutputAttribute;
 using blender::fn::GMutableSpan;
 using blender::fn::GSpan;
 using blender::fn::GVArray_For_GSpan;
@@ -334,8 +336,20 @@ bool BuiltinCustomDataLayerProvider::exists(const GeometryComponent &component)
   return data != nullptr;
 }
 
+static bool custom_data_layer_matches_attribute_id(const CustomDataLayer &layer,
+                                                   const AttributeIDRef &attribute_id)
+{
+  if (!attribute_id) {
+    return false;
+  }
+  if (attribute_id.is_anonymous()) {
+    return layer.anonymous_id == &attribute_id.anonymous_id();
+  }
+  return layer.name == attribute_id.name();
+}
+
 ReadAttributeLookup CustomDataAttributeProvider::try_get_for_read(
-    const GeometryComponent &component, const StringRef attribute_name) const
+    const GeometryComponent &component, const AttributeIDRef &attribute_id) const
 {
   const CustomData *custom_data = custom_data_access_.get_const_custom_data(component);
   if (custom_data == nullptr) {
@@ -343,7 +357,7 @@ ReadAttributeLookup CustomDataAttributeProvider::try_get_for_read(
   }
   const int domain_size = component.attribute_domain_size(domain_);
   for (const CustomDataLayer &layer : Span(custom_data->layers, custom_data->totlayer)) {
-    if (layer.name != attribute_name) {
+    if (!custom_data_layer_matches_attribute_id(layer, attribute_id)) {
       continue;
     }
     const CustomDataType data_type = (CustomDataType)layer.type;
@@ -368,7 +382,7 @@ ReadAttributeLookup CustomDataAttributeProvider::try_get_for_read(
 }
 
 WriteAttributeLookup CustomDataAttributeProvider::try_get_for_write(
-    GeometryComponent &component, const StringRef attribute_name) const
+    GeometryComponent &component, const AttributeIDRef &attribute_id) const
 {
   CustomData *custom_data = custom_data_access_.get_custom_data(component);
   if (custom_data == nullptr) {
@@ -376,10 +390,17 @@ WriteAttributeLookup CustomDataAttributeProvider::try_get_for_write(
   }
   const int domain_size = component.attribute_domain_size(domain_);
   for (CustomDataLayer &layer : MutableSpan(custom_data->layers, custom_data->totlayer)) {
-    if (layer.name != attribute_name) {
+    if (!custom_data_layer_matches_attribute_id(layer, attribute_id)) {
       continue;
     }
-    CustomData_duplicate_referenced_layer_named(custom_data, layer.type, layer.name, domain_size);
+    if (attribute_id.is_named()) {
+      CustomData_duplicate_referenced_layer_named(
+          custom_data, layer.type, layer.name, domain_size);
+    }
+    else {
+      CustomData_duplicate_referenced_layer_anonymous(
+          custom_data, layer.type, &attribute_id.anonymous_id(), domain_size);
+    }
     const CustomDataType data_type = (CustomDataType)layer.type;
     switch (data_type) {
       case CD_PROP_FLOAT:
@@ -402,7 +423,7 @@ WriteAttributeLookup CustomDataAttributeProvider::try_get_for_write(
 }
 
 bool CustomDataAttributeProvider::try_delete(GeometryComponent &component,
-                                             const StringRef attribute_name) const
+                                             const AttributeIDRef &attribute_id) const
 {
   CustomData *custom_data = custom_data_access_.get_custom_data(component);
   if (custom_data == nullptr) {
@@ -411,7 +432,8 @@ bool CustomDataAttributeProvider::try_delete(GeometryComponent &component,
   const int domain_size = component.attribute_domain_size(domain_);
   for (const int i : IndexRange(custom_data->totlayer)) {
     const CustomDataLayer &layer = custom_data->layers[i];
-    if (this->type_is_supported((CustomDataType)layer.type) && layer.name == attribute_name) {
+    if (this->type_is_supported((CustomDataType)layer.type) &&
+        custom_data_layer_matches_attribute_id(layer, attribute_id)) {
       CustomData_free_layer(custom_data, layer.type, domain_size, i);
       return true;
     }
@@ -419,24 +441,39 @@ bool CustomDataAttributeProvider::try_delete(GeometryComponent &component,
   return false;
 }
 
-static bool add_named_custom_data_layer_from_attribute_init(const StringRef attribute_name,
-                                                            CustomData &custom_data,
-                                                            const CustomDataType data_type,
-                                                            const int domain_size,
-                                                            const AttributeInit &initializer)
+static void *add_generic_custom_data_layer(CustomData &custom_data,
+                                           const CustomDataType data_type,
+                                           const eCDAllocType alloctype,
+                                           void *layer_data,
+                                           const int domain_size,
+                                           const AttributeIDRef &attribute_id)
 {
-  char attribute_name_c[MAX_NAME];
-  attribute_name.copy(attribute_name_c);
+  if (attribute_id.is_named()) {
+    char attribute_name_c[MAX_NAME];
+    attribute_id.name().copy(attribute_name_c);
+    return CustomData_add_layer_named(
+        &custom_data, data_type, CD_DEFAULT, nullptr, domain_size, attribute_name_c);
+  }
+  const AnonymousAttributeID &anonymous_id = attribute_id.anonymous_id();
+  return CustomData_add_layer_anonymous(
+      &custom_data, data_type, alloctype, layer_data, domain_size, &anonymous_id);
+}
 
+static bool add_custom_data_layer_from_attribute_init(const AttributeIDRef &attribute_id,
+                                                      CustomData &custom_data,
+                                                      const CustomDataType data_type,
+                                                      const int domain_size,
+                                                      const AttributeInit &initializer)
+{
   switch (initializer.type) {
     case AttributeInit::Type::Default: {
-      void *data = CustomData_add_layer_named(
-          &custom_data, data_type, CD_DEFAULT, nullptr, domain_size, attribute_name_c);
+      void *data = add_generic_custom_data_layer(
+          custom_data, data_type, CD_DEFAULT, nullptr, domain_size, attribute_id);
       return data != nullptr;
     }
     case AttributeInit::Type::VArray: {
-      void *data = CustomData_add_layer_named(
-          &custom_data, data_type, CD_DEFAULT, nullptr, domain_size, attribute_name_c);
+      void *data = add_generic_custom_data_layer(
+          custom_data, data_type, CD_DEFAULT, nullptr, domain_size, attribute_id);
       if (data == nullptr) {
         return false;
       }
@@ -446,8 +483,8 @@ static bool add_named_custom_data_layer_from_attribute_init(const StringRef attr
     }
     case AttributeInit::Type::MoveArray: {
       void *source_data = static_cast<const AttributeInitMove &>(initializer).data;
-      void *data = CustomData_add_layer_named(
-          &custom_data, data_type, CD_ASSIGN, source_data, domain_size, attribute_name_c);
+      void *data = add_generic_custom_data_layer(
+          custom_data, data_type, CD_ASSIGN, source_data, domain_size, attribute_id);
       if (data == nullptr) {
         MEM_freeN(source_data);
         return false;
@@ -461,7 +498,7 @@ static bool add_named_custom_data_layer_from_attribute_init(const StringRef attr
 }
 
 bool CustomDataAttributeProvider::try_create(GeometryComponent &component,
-                                             const StringRef attribute_name,
+                                             const AttributeIDRef &attribute_id,
                                              const AttributeDomain domain,
                                              const CustomDataType data_type,
                                              const AttributeInit &initializer) const
@@ -477,13 +514,13 @@ bool CustomDataAttributeProvider::try_create(GeometryComponent &component,
     return false;
   }
   for (const CustomDataLayer &layer : Span(custom_data->layers, custom_data->totlayer)) {
-    if (layer.name == attribute_name) {
+    if (custom_data_layer_matches_attribute_id(layer, attribute_id)) {
       return false;
     }
   }
   const int domain_size = component.attribute_domain_size(domain_);
-  add_named_custom_data_layer_from_attribute_init(
-      attribute_name, *custom_data, data_type, domain_size, initializer);
+  add_custom_data_layer_from_attribute_init(
+      attribute_id, *custom_data, data_type, domain_size, initializer);
   return true;
 }
 
@@ -498,7 +535,14 @@ bool CustomDataAttributeProvider::foreach_attribute(const GeometryComponent &com
     const CustomDataType data_type = (CustomDataType)layer.type;
     if (this->type_is_supported(data_type)) {
       AttributeMetaData meta_data{domain_, data_type};
-      if (!callback(layer.name, meta_data)) {
+      AttributeIDRef attribute_id;
+      if (layer.anonymous_id != nullptr) {
+        attribute_id = layer.anonymous_id;
+      }
+      else {
+        attribute_id = layer.name;
+      }
+      if (!callback(attribute_id, meta_data)) {
         return false;
       }
     }
@@ -507,7 +551,7 @@ bool CustomDataAttributeProvider::foreach_attribute(const GeometryComponent &com
 }
 
 ReadAttributeLookup NamedLegacyCustomDataProvider::try_get_for_read(
-    const GeometryComponent &component, const StringRef attribute_name) const
+    const GeometryComponent &component, const AttributeIDRef &attribute_id) const
 {
   const CustomData *custom_data = custom_data_access_.get_const_custom_data(component);
   if (custom_data == nullptr) {
@@ -515,7 +559,7 @@ ReadAttributeLookup NamedLegacyCustomDataProvider::try_get_for_read(
   }
   for (const CustomDataLayer &layer : Span(custom_data->layers, custom_data->totlayer)) {
     if (layer.type == stored_type_) {
-      if (layer.name == attribute_name) {
+      if (custom_data_layer_matches_attribute_id(layer, attribute_id)) {
         const int domain_size = component.attribute_domain_size(domain_);
         return {as_read_attribute_(layer.data, domain_size), domain_};
       }
@@ -525,7 +569,7 @@ ReadAttributeLookup NamedLegacyCustomDataProvider::try_get_for_read(
 }
 
 WriteAttributeLookup NamedLegacyCustomDataProvider::try_get_for_write(
-    GeometryComponent &component, const StringRef attribute_name) const
+    GeometryComponent &component, const AttributeIDRef &attribute_id) const
 {
   CustomData *custom_data = custom_data_access_.get_custom_data(component);
   if (custom_data == nullptr) {
@@ -533,7 +577,7 @@ WriteAttributeLookup NamedLegacyCustomDataProvider::try_get_for_write(
   }
   for (CustomDataLayer &layer : MutableSpan(custom_data->layers, custom_data->totlayer)) {
     if (layer.type == stored_type_) {
-      if (layer.name == attribute_name) {
+      if (custom_data_layer_matches_attribute_id(layer, attribute_id)) {
         const int domain_size = component.attribute_domain_size(domain_);
         void *data_old = layer.data;
         void *data_new = CustomData_duplicate_referenced_layer_named(
@@ -549,7 +593,7 @@ WriteAttributeLookup NamedLegacyCustomDataProvider::try_get_for_write(
 }
 
 bool NamedLegacyCustomDataProvider::try_delete(GeometryComponent &component,
-                                               const StringRef attribute_name) const
+                                               const AttributeIDRef &attribute_id) const
 {
   CustomData *custom_data = custom_data_access_.get_custom_data(component);
   if (custom_data == nullptr) {
@@ -558,7 +602,7 @@ bool NamedLegacyCustomDataProvider::try_delete(GeometryComponent &component,
   for (const int i : IndexRange(custom_data->totlayer)) {
     const CustomDataLayer &layer = custom_data->layers[i];
     if (layer.type == stored_type_) {
-      if (layer.name == attribute_name) {
+      if (custom_data_layer_matches_attribute_id(layer, attribute_id)) {
         const int domain_size = component.attribute_domain_size(domain_);
         CustomData_free_layer(custom_data, stored_type_, domain_size, i);
         custom_data_access_.update_custom_data_pointers(component);
@@ -627,11 +671,11 @@ CustomDataAttributes &CustomDataAttributes::operator=(const CustomDataAttributes
   return *this;
 }
 
-std::optional<GSpan> CustomDataAttributes::get_for_read(const StringRef name) const
+std::optional<GSpan> CustomDataAttributes::get_for_read(const AttributeIDRef &attribute_id) const
 {
   BLI_assert(size_ != 0);
   for (const CustomDataLayer &layer : Span(data.layers, data.totlayer)) {
-    if (layer.name == name) {
+    if (custom_data_layer_matches_attribute_id(layer, attribute_id)) {
       const CPPType *cpp_type = custom_data_type_to_cpp_type((CustomDataType)layer.type);
       BLI_assert(cpp_type != nullptr);
       return GSpan(*cpp_type, layer.data, size_);
@@ -645,13 +689,13 @@ std::optional<GSpan> CustomDataAttributes::get_for_read(const StringRef name) co
  * value if the attribute doesn't exist. If no default value is provided, the default value for the
  * type will be used.
  */
-GVArrayPtr CustomDataAttributes::get_for_read(const StringRef name,
+GVArrayPtr CustomDataAttributes::get_for_read(const AttributeIDRef &attribute_id,
                                               const CustomDataType data_type,
                                               const void *default_value) const
 {
   const CPPType *type = blender::bke::custom_data_type_to_cpp_type(data_type);
 
-  std::optional<GSpan> attribute = this->get_for_read(name);
+  std::optional<GSpan> attribute = this->get_for_read(attribute_id);
   if (!attribute) {
     const int domain_size = this->size_;
     return std::make_unique<GVArray_For_SingleValue>(
@@ -666,12 +710,12 @@ GVArrayPtr CustomDataAttributes::get_for_read(const StringRef name,
   return conversions.try_convert(std::make_unique<GVArray_For_GSpan>(*attribute), *type);
 }
 
-std::optional<GMutableSpan> CustomDataAttributes::get_for_write(const StringRef name)
+std::optional<GMutableSpan> CustomDataAttributes::get_for_write(const AttributeIDRef &attribute_id)
 {
   /* If this assert hits, it most likely means that #reallocate was not called at some point. */
   BLI_assert(size_ != 0);
   for (CustomDataLayer &layer : MutableSpan(data.layers, data.totlayer)) {
-    if (layer.name == name) {
+    if (custom_data_layer_matches_attribute_id(layer, attribute_id)) {
       const CPPType *cpp_type = custom_data_type_to_cpp_type((CustomDataType)layer.type);
       BLI_assert(cpp_type != nullptr);
       return GMutableSpan(*cpp_type, layer.data, size_);
@@ -680,30 +724,29 @@ std::optional<GMutableSpan> CustomDataAttributes::get_for_write(const StringRef
   return {};
 }
 
-bool CustomDataAttributes::create(const StringRef name, const CustomDataType data_type)
+bool CustomDataAttributes::create(const AttributeIDRef &attribute_id,
+                                  const CustomDataType data_type)
 {
-  char name_c[MAX_NAME];
-  name.copy(name_c);
-  void *result = CustomData_add_layer_named(&data, data_type, CD_DEFAULT, nullptr, size_, name_c);
+  void *result = add_generic_custom_data_layer(
+      data, data_type, CD_DEFAULT, nullptr, size_, attribute_id);
   return result != nullptr;
 }
 
-bool CustomDataAttributes::create_by_move(const blender::StringRef name,
+bool CustomDataAttributes::create_by_move(const AttributeIDRef &attribute_id,
                                           const CustomDataType data_type,
                                           void *buffer)
 {
-  char name_c[MAX_NAME];
-  name.copy(name_c);
-  void *result = CustomData_add_layer_named(&data, data_type, CD_ASSIGN, buffer, size_, name_c);
+  void *result = add_generic_custom_data_layer(
+      data, data_type, CD_ASSIGN, buffer, size_, attribute_id);
   return result != nullptr;
 }
 
-bool CustomDataAttributes::remove(const blender::StringRef name)
+bool CustomDataAttributes::remove(const AttributeIDRef &attribute_id)
 {
   bool result = false;
   for (const int i : IndexRange(data.totlayer)) {
     const CustomDataLayer &layer = data.layers[i];
-    if (layer.name == name) {
+    if (custom_data_layer_matches_attribute_id(layer, attribute_id)) {
       CustomData_free_layer(&data, layer.type, size_, i);
       result = true;
     }
@@ -722,7 +765,14 @@ bool CustomDataAttributes::foreach_attribute(const AttributeForeachCallback call
 {
   for (const CustomDataLayer &layer : Span(data.layers, data.totlayer)) {
     AttributeMetaData meta_data{domain, (CustomDataType)layer.type};
-    if (!callback(layer.name, meta_data)) {
+    AttributeIDRef attribute_id;
+    if (layer.anonymous_id != nullptr) {
+      attribute_id = layer.anonymous_id;
+    }
+    else {
+      attribute_id = layer.name;
+    }
+    if (!callback(attribute_id, meta_data)) {
       return false;
     }
   }
@@ -766,21 +816,23 @@ bool GeometryComponent::attribute_is_builtin(const blender::StringRef attribute_
 }
 
 blender::bke::ReadAttributeLookup GeometryComponent::attribute_try_get_for_read(
-    const StringRef attribute_name) const
+    const AttributeIDRef &attribute_id) const
 {
   using namespace blender::bke;
   const ComponentAttributeProviders *providers = this->get_attribute_providers();
   if (providers == nullptr) {
     return {};
   }
-  const BuiltinAttributeProvider *builtin_provider =
-      providers->builtin_attribute_providers().lookup_default_as(attribute_name, nullptr);
-  if (builtin_provider != nullptr) {
-    return {builtin_provider->try_get_for_read(*this), builtin_provider->domain()};
+  if (attribute_id.is_named()) {
+    const BuiltinAttributeProvider *builtin_provider =
+        providers->builtin_attribute_providers().lookup_default_as(attribute_id.name(), nullptr);
+    if (builtin_provider != nullptr) {
+      return {builtin_provider->try_get_for_read(*this), builtin_provider->domain()};
+    }
   }
   for (const DynamicAttributesProvider *dynamic_provider :
        providers->dynamic_attribute_providers()) {
-    ReadAttributeLookup attribute = dynamic_provider->try_get_for_read(*this, attribute_name);
+    ReadAttributeLookup attribute = dynamic_provider->try_get_for_read(*this, attribute_id);
     if (attribute) {
       return attribute;
     }
@@ -800,21 +852,23 @@ std::unique_ptr<blender::fn::GVArray> GeometryComponent::attribute_try_adapt_dom
 }
 
 blender::bke::WriteAttributeLookup GeometryComponent::attribute_try_get_for_write(
-    const StringRef attribute_name)
+    const AttributeIDRef &attribute_id)
 {
   using namespace blender::bke;
   const ComponentAttributeProviders *providers = this->get_attribute_providers();
   if (providers == nullptr) {
     return {};
   }
-  const BuiltinAttributeProvider *builtin_provider =
-      providers->builtin_attribute_providers().lookup_default_as(attribute_name, nullptr);
-  if (builtin_provider != nullptr) {
-    return {builtin_provider->try_get_for_write(*this), builtin_provider->domain()};
+  if (attribute_id.is_named()) {
+    const BuiltinAttributeProvider *builtin_provider =
+        providers->builtin_attribute_providers().lookup_default_as(attribute_id.name(), nullptr);
+    if (builtin_provider != nullptr) {
+      return {builtin_provider->try_get_for_write(*this), builtin_provider->domain()};
+    }
   }
   for (const DynamicAttributesProvider *dynamic_provider :
        providers->dynamic_attribute_providers()) {
-    WriteAttributeLookup attribute = dynamic_provider->try_get_for_write(*this, attribute_name);
+    WriteAttributeLookup attribute = dynamic_provider->try_get_for_write(*this, attribute_id);
     if (attribute) {
       return attribute;
     }
@@ -822,53 +876,57 @@ blender::bke::WriteAttributeLookup GeometryComponent::attribute_try_get_for_writ
   return {};
 }
 
-bool GeometryComponent::attribute_try_delete(const StringRef attribute_name)
+bool GeometryComponent::attribute_try_delete(const AttributeIDRef &attribute_id)
 {
   using namespace blender::bke;
   const ComponentAttributeProviders *providers = this->get_attribute_providers();
   if (providers == nullptr) {
     return {};
   }
-  const BuiltinAttributeProvider *builtin_provider =
-      providers->builtin_attribute_providers().lookup_default_as(attribute_name, nullptr);
-  if (builtin_provider != nullptr) {
-    return builtin_provider->try_delete(*this);
+  if (attribute_id.is_named()) {
+    const BuiltinAttributeProvider *builtin_provider =
+        providers->builtin_attribute_providers().lookup_default_as(attribute_id.name(), nullptr);
+    if (builtin_provider != nullptr) {
+      return builtin_provider->try_delete(*this);
+    }
   }
   bool success = false;
   for (const DynamicAttributesProvider *dynamic_provider :
        providers->dynamic_attribute_providers()) {
-    success = dynamic_provider->try_delete(*this, attribute_name) || success;
+    success = dynamic_provider->try_delete(*this, attribute_id) || success;
   }
   return success;
 }
 
-bool GeometryComponent::attribute_try_create(const StringRef attribute_name,
+bool GeometryComponent::attribute_try_create(const AttributeIDRef &attribute_id,
                                              const AttributeDomain domain,
                                              const CustomDataType data_type,
                                              const AttributeInit &initializer)
 {
   using namespace blender::bke;
-  if (attribute_name.is_empty()) {
+  if (!attribute_id) {
     return false;
   }
   const ComponentAttributeProviders *providers = this->get_attribute_providers();
   if (providers == nullptr) {
     return false;
   }
-  const BuiltinAttributeProvider *builtin_provider =
-      providers->builtin_attribute_providers().lookup_default_as(attribute_name, nullptr);
-  if (builtin_provider != nullptr) {
-    if (builtin_provider->domain() != domain) {
-      return false;
-    }
-    if (builtin_provider->data_type() != data_type) {
-      return false;
+  if (attribute_id.is_named()) {
+    const BuiltinAttributeProvider *builtin_provider =
+        providers->builtin_attribute_providers().lookup_default_as(attribute_id.name(), nullptr);
+    if (builtin_provider != nullptr) {
+      if (builtin_provider->domain() != domain) {
+        return false;
+      }
+      if (builtin_provider->data_type() != data_type) {
+        return false;
+      }
+      return builtin_provider->try_create(*this, initializer);
     }
-    return builtin_provider->try_create(*this, initializer);
   }
   for (const DynamicAttributesProvider *dynamic_provider :
        providers->dynamic_attribute_providers()) {
-    if (dynamic_provider->try_create(*this, attribute_name, domain, data_type, initializer)) {
+    if (dynamic_provider->try_create(*this, attribute_id, domain, data_type, initializer)) {
       return true;
     }
   }
@@ -894,13 +952,14 @@ bool GeometryComponent::attribute_try_create_builtin(const blender::StringRef at
   return builtin_provider->try_create(*this, initializer);
 }
 
-Set<std::string> GeometryComponent::attribute_names() const
+Set<AttributeIDRef> GeometryComponent::attribute_ids() const
 {
-  Set<std::string> attributes;
-  this->attribute_foreach([&](StringRefNull name, const AttributeMetaData &UNUSED(meta_data)) {
-    attributes.add(name);
-    return true;
-  });
+  Set<AttributeIDRef> attributes;
+  this->attribute_foreach(
+      [&](const AttributeIDRef &attribute_id, const AttributeMetaData &UNUSED(meta_data)) {
+        attributes.add(attribute_id);
+        return true;
+      });
   return attributes;
 }
 
@@ -931,9 +990,9 @@ bool GeometryComponent::attribute_foreach(const AttributeForeachCallback callbac
   }
   for (const DynamicAttributesProvider *provider : providers->dynamic_attribute_providers()) {
     const bool continue_loop = provider->foreach_attribute(
-        *this, [&](StringRefNull name, const AttributeMetaData &meta_data) {
-          if (handled_attribute_names.add(name)) {
-            return callback(name, meta_data);
+        *this, [&](const AttributeIDRef &attribute_id, const AttributeMetaData &meta_data) {
+          if (attribute_id.is_anonymous() || handled_attribute_names.add(attribute_id.name())) {
+            return callback(attribute_id, meta_data);
           }
           return true;
         });
@@ -945,9 +1004,9 @@ bool GeometryComponent::attribute_foreach(const AttributeForeachCallback callbac
   return true;
 }
 
-bool GeometryComponent::attribute_exists(const blender::StringRef attribute_name) const
+bool GeometryComponent::attribute_exists(const AttributeIDRef &attribute_id) const
 {
-  blender::bke::ReadAttributeLookup attribute = this->attribute_try_get_for_read(attribute_name);
+  blender::bke::ReadAttributeLookup attribute = this->attribute_try_get_for_read(attribute_id);
   if (attribute) {
     return true;
   }
@@ -955,16 +1014,17 @@ bool GeometryComponent::attribute_exists(const blender::StringRef attribute_name
 }
 
 std::optional<AttributeMetaData> GeometryComponent::attribute_get_meta_data(
-    const StringRef attribute_name) const
+    const AttributeIDRef &attribute_id) const
 {
   std::optional<AttributeMetaData> result{std::nullopt};
-  this->attribute_foreach([&](StringRefNull name, const AttributeMetaData &meta_data) {
-    if (attribute_name == name) {
-      result = meta_data;
-      return false;
-    }
-    return true;
-  });
+  this->attribute_foreach(
+      [&](const AttributeIDRef &current_attribute_id, const AttributeMetaData &meta_data) {
+        if (attribute_id == current_attribute_id) {
+          result = meta_data;
+          return false;
+        }
+        return true;
+      });
   return result;
 }
 
@@ -977,11 +1037,11 @@ static std::unique_ptr<blender::fn::GVArray> try_adapt_data_type(
 }
 
 std::unique_ptr<blender::fn::GVArray> GeometryComponent::attribute_try_get_for_read(
-    const StringRef attribute_name,
+    const AttributeIDRef &attribute_id,
     const AttributeDomain domain,
     const CustomDataType data_type) const
 {
-  blender::bke::ReadAttributeLookup attribute = this->attribute_try_get_for_read(attribute_name);
+  blender::bke::ReadAttributeLookup attribute = this->attribute_try_get_for_read(attribute_id);
   if (!attribute) {
     return {};
   }
@@ -1007,13 +1067,13 @@ std::unique_ptr<blender::fn::GVArray> GeometryComponent::attribute_try_get_for_r
 }
 
 std::unique_ptr<blender::bke::GVArray> GeometryComponent::attribute_try_get_for_read(
-    const StringRef attribute_name, const AttributeDomain domain) const
+    const AttributeIDRef &attribute_id, const AttributeDomain domain) const
 {
   if (!this->attribute_domain_supported(domain)) {
     return {};
   }
 
-  blender::bke::ReadAttributeLookup attribute = this->attribute_try_get_for_read(attribute_name);
+  blender::bke::ReadAttributeLookup attribute = this->attribute_try_get_for_read(attribute_id);
   if (!attribute) {
     return {};
   }
@@ -1026,9 +1086,9 @@ std::unique_ptr<blender::bke::GVArray> GeometryComponent::attribute_try_get_for_
 }
 
 blender::bke::ReadAttributeLookup GeometryComponent::attribute_try_get_for_read(
-    const blender::StringRef attribute_name, const CustomDataType data_type) const
+    const AttributeIDRef &attribute_id, const CustomDataType data_type) const
 {
-  blender::bke::ReadAttributeLookup attribute = this->attribute_try_get_for_read(attribute_name);
+  blender::bke::ReadAttributeLookup attribute = this->attribute_try_get_for_read(attribute_id);
   if (!attribute) {
     return {};
   }
@@ -1043,13 +1103,13 @@ blender::bke::ReadAttributeLookup GeometryComponent::attribute_try_get_for_read(
 }
 
 std::unique_ptr<blender::bke::GVArray> GeometryComponent::attribute_get_for_read(
-    const StringRef attribute_name,
+    const AttributeIDRef &attribute_id,
     const AttributeDomain domain,
     const CustomDataType data_type,
     const void *default_value) const
 {
   std::unique_ptr<blender::bke::GVArray> varray = this->attribute_try_get_for_read(
-      attribute_name, domain, data_type);
+      attribute_id, domain, data_type);
   if (varray) {
     return varray;
   }
@@ -1065,15 +1125,22 @@ class GVMutableAttribute_For_OutputAttribute
     : public blender::fn::GVMutableArray_For_GMutableSpan {
  public:
   GeometryComponent *component;
-  std::string final_name;
+  std::string attribute_name;
+  blender::bke::WeakAnonymousAttributeID anonymous_attribute_id;
 
   GVMutableAttribute_For_OutputAttribute(GMutableSpan data,
                                          GeometryComponent &component,
-                                         std::string final_name)
-      : blender::fn::GVMutableArray_For_GMutableSpan(data),
-        component(&component),
-        final_name(std::move(final_name))
+                                         const AttributeIDRef &attribute_id)
+      : blender::fn::GVMutableArray_For_GMutableSpan(data), component(&component)
   {
+    if (attribute_id.is_named()) {
+      this->attribute_name = attribute_id.name();
+    }
+    else {
+      const AnonymousAttributeID *anonymous_id = &attribute_id.anonymous_id();
+      BKE_anonymous_attribute_id_increment_weak(anonymous_id);
+      this->anonymous_attribute_id = blender::bke::WeakAnonymousAttributeID{anonymous_id};
+    }
   }
 
   ~GVMutableAttribute_For_OutputAttribute() override
@@ -1083,7 +1150,7 @@ class GVMutableAttribute_For_OutputAttribute
   }
 };
 
-static void save_output_attribute(blender::bke::OutputAttribute &output_attribute)
+static void save_output_attribute(OutputAttribute &output_attribute)
 {
   using namespace blender;
   using namespace blender::fn;
@@ -1093,21 +1160,28 @@ static void save_output_attribute(blender::bke::OutputAttribute &output_attribut
       dynamic_cast<GVMutableAttribute_For_OutputAttribute &>(output_attribute.varray());
 
   GeometryComponent &component = *varray.component;
-  const StringRefNull name = varray.final_name;
+  AttributeIDRef attribute_id;
+  if (!varray.attribute_name.empty()) {
+    attribute_id = varray.attribute_name;
+  }
+  else {
+    attribute_id = varray.anonymous_attribute_id.extract();
+  }
   const AttributeDomain domain = output_attribute.domain();
   const CustomDataType data_type = output_attribute.custom_data_type();
   const CPPType &cpp_type = output_attribute.cpp_type();
 
-  component.attribute_try_delete(name);
-  if (!component.attribute_try_create(
-          varray.final_name, domain, data_type, AttributeInitDefault())) {
-    CLOG_WARN(&LOG,
-              "Could not create the '%s' attribute with type '%s'.",
-              name.c_str(),
-              cpp_type.name().c_str());
+  component.attribute_try_delete(attribute_id);
+  if (!component.attribute_try_create(attribute_id, domain, data_type, AttributeInitDefault())) {
+    if (!varray.attribute_name.empty()) {
+      CLOG_WARN(&LOG,
+                "Could not create the '%s' attribute with type '%s'.",
+                varray.attribute_name.c_str(),
+                cpp_type.name().c_str());
+    }
     return;
   }
-  WriteAttributeLookup write_attribute = component.attribute_try_get_for_write(name);
+  WriteAttributeLookup write_attribute = component.attribute_try_get_for_write(attribute_id);
   BUFFER_FOR_CPP_TYPE_VALUE(varray.type(), buffer);
   for (const int i : IndexRange(varray.size())) {
     varray.get(i, buffer);
@@ -1115,19 +1189,18 @@ static void save_output_attribute(blender::bke::OutputAttribute &output_attribut
   }
 }
 
-static blender::bke::OutputAttribute create_output_attribute(
-    GeometryComponent &component,
-    const blender::StringRef attribute_name,
-    const AttributeDomain domain,
-    const CustomDataType data_type,
-    const bool ignore_old_values,
-    const void *default_value)
+static OutputAttribute create_output_attribute(GeometryComponent &component,
+                                               const AttributeIDRef &attribute_id,
+                                               const AttributeDomain domain,
+                                               const CustomDataType data_type,
+                                               const bool ignore_old_values,
+                                               const void *default_value)
 {
   using namespace blender;
   using namespace blender::fn;
   using namespace blender::bke;
 
-  if (attribute_name.is_empty()) {
+  if (!attribute_id) {
     return {};
   }
 
@@ -1135,7 +1208,8 @@ static blender::bke::OutputAttribute create_output_attribute(
   BLI_assert(cpp_type != nullptr);
   const nodes::DataTypeConversions &conversions = nodes::get_implicit_type_conversions();
 
-  if (component.attribute_is_builtin(attribute_name)) {
+  if (attribute_id.is_named() && component.attribute_is_builtin(attribute_id.name())) {
+    const StringRef attribute_name = attribute_id.name();
     WriteAttributeLookup attribute = component.attribute_try_get_for_write(attribute_name);
     if (!attribute) {
       if (default_value) {
@@ -1169,18 +1243,18 @@ static blender::bke::OutputAttribute create_output_attribute(
 
   const int domain_size = component.attribute_domain_size(domain);
 
-  WriteAttributeLookup attribute = component.attribute_try_get_for_write(attribute_name);
+  WriteAttributeLookup attribute = component.attribute_try_get_for_write(attribute_id);
   if (!attribute) {
     if (default_value) {
       const GVArray_For_SingleValueRef default_varray{*cpp_type, domain_size, default_value};
       component.attribute_try_create(
-          attribute_name, domain, data_type, AttributeInitVArray(&default_varray));
+          attribute_id, domain, data_type, AttributeInitVArray(&default_varray));
     }
     else {
-      component.attribute_try_create(attribute_name, domain, data_type, AttributeInitDefault());
+      component.attribute_try_create(attribute_id, domain, data_type, AttributeInitDefault());
     }
 
-    attribute = component.attribute_try_get_for_write(attribute_name);
+    attribute = component.attribute_try_get_for_write(attribute_id);
     if (!attribute) {
       /* Can't create the attribute. */
       return {};
@@ -1202,28 +1276,88 @@ static blender::bke::OutputAttribute create_output_attribute(
   else {
     /* Fill the temporary array with values from the existing attribute. */
     GVArrayPtr old_varray = component.attribute_get_for_read(
-        attribute_name, domain, data_type, default_value);
+        attribute_id, domain, data_type, default_value);
     old_varray->materialize_to_uninitialized(IndexRange(domain_size), data);
   }
   GVMutableArrayPtr varray = std::make_unique<GVMutableAttribute_For_OutputAttribute>(
-      GMutableSpan{*cpp_type, data, domain_size}, component, attribute_name);
+      GMutableSpan{*cpp_type, data, domain_size}, component, attribute_id);
 
   return OutputAttribute(std::move(varray), domain, save_output_attribute, true);
 }
 
-blender::bke::OutputAttribute GeometryComponent::attribute_try_get_for_output(
-    const StringRef attribute_name,
-    const AttributeDomain domain,
-    const CustomDataType data_type,
-    const void *default_value)
+OutputAttribute GeometryComponent::attribute_try_get_for_output(const AttributeIDRef &attribute_id,
+                                                                const AttributeDomain domain,
+                                                                const CustomDataType data_type,
+                                                                const void *default_value)
 {
-  return create_output_attribute(*this, attribute_name, domain, data_type, false, default_value);
+  return create_output_attribute(*this, attribute_id, domain, data_type, false, default_value);
 }
 
-blender::bke::OutputAttribute GeometryComponent::attribute_try_get_for_output_only(
-    const blender::StringRef attribute_name,
+OutputAttribute GeometryComponent::attribute_try_get_for_output_only(
+    const AttributeIDRef &attribute_id,
     const AttributeDomain domain,
     const CustomDataType data_type)
 {
-  return create_output_attribute(*this, attribute_name, domain, data_type, true, nullptr);
+  return create_output_attribute(*this, attribute_id, domain, data_type, true, nullptr);
+}
+
+namespace blender::bke {
+
+const GVArray *AttributeFieldInput::get_varray_for_context(const fn::FieldContext &context,
+                                                           IndexMask UNUSED(mask),
+                                                           ResourceScope &scope) const
+{
+  if (const GeometryComponentFieldContext *geometry_context =
+          dynamic_cast<const GeometryComponentFieldContext *>(&context)) {
+    const GeometryComponent &component = geometry_context->geometry_component();
+    const AttributeDomain domain = geometry_context->domain();
+    const CustomDataType data_type = cpp_type_to_custom_data_type(*type_);
+    GVArrayPtr attribute = component.attribute_try_get_for_read(name_, domain, data_type);
+    return scope.add(std::move(attribute), __func__);
+  }
+  return nullptr;
+}
+
+uint64_t AttributeFieldInput::hash() const
+{
+  return get_default_hash_2(name_, type_);
+}
+
+bool AttributeFieldInput::is_equal_to(const fn::FieldNode &other) const
+{
+  if (const AttributeFieldInput *other_typed = dynamic_cast<const AttributeFieldInput *>(&other)) {
+    return name_ == other_typed->name_ && type_ == other_typed->type_;
+  }
+  return false;
+}
+
+const GVArray *AnonymousAttributeFieldInput::get_varray_for_context(
+    const fn::FieldContext &context, IndexMask UNUSED(mask), ResourceScope &scope) const
+{
+  if (const GeometryComponentFieldContext *geometry_context =
+          dynamic_cast<const GeometryComponentFieldContext *>(&context)) {
+    const GeometryComponent &component = geometry_context->geometry_component();
+    const AttributeDomain domain = geometry_context->domain();
+    const CustomDataType data_type = cpp_type_to_custom_data_type(*type_);
+    GVArrayPtr attribute = component.attribute_try_get_for_read(
+        anonymous_id_.get(), domain, data_type);
+    return scope.add(std::move(attribute), __func__);
+  }
+  return nullptr;
+}
+
+uint64_t AnonymousAttributeFieldInput::hash() const
+{
+  return get_default_hash_2(anonymous_id_.get(), type_);
 }
+
+bool AnonymousAttributeFieldInput::is_equal_to(const fn::FieldNode &other) const
+{
+  if (const AnonymousAttributeFieldInput *other_typed =
+          dynamic_cast<const AnonymousAttributeFieldInput *>(&other)) {
+    return anonymous_id_.get() == other_typed->anonymous_id_.get() && type_ == other_typed->type_;
+  }
+  return false;
+}
+
+}  // namespace blender::bke
diff --git a/source/blender/blenkernel/intern/attribute_access_intern.hh b/source/blender/blenkernel/intern/attribute_access_intern.hh
index b3a795faa30..261cb26d4e5 100644
--- a/source/blender/blenkernel/intern/attribute_access_intern.hh
+++ b/source/blender/blenkernel/intern/attribute_access_intern.hh
@@ -116,12 +116,13 @@ class BuiltinAttributeProvider {
 class DynamicAttributesProvider {
  public:
   virtual ReadAttributeLookup try_get_for_read(const GeometryComponent &component,
-                                               const StringRef attribute_name) const = 0;
+                                               const AttributeIDRef &attribute_id) const = 0;
   virtual WriteAttributeLookup try_get_for_write(GeometryComponent &component,
-                                                 const StringRef attribute_name) const = 0;
-  virtual bool try_delete(GeometryComponent &component, const StringRef attribute_name) const = 0;
+                                                 const AttributeIDRef &attribute_id) const = 0;
+  virtual bool try_delete(GeometryComponent &component,
+                          const AttributeIDRef &attribute_id) const = 0;
   virtual bool try_create(GeometryComponent &UNUSED(component),
-                          const StringRef UNUSED(attribute_name),
+                          const AttributeIDRef &UNUSED(attribute_id),
                           const AttributeDomain UNUSED(domain),
                           const CustomDataType UNUSED(data_type),
                           const AttributeInit &UNUSED(initializer)) const
@@ -154,15 +155,15 @@ class CustomDataAttributeProvider final : public DynamicAttributesProvider {
   }
 
   ReadAttributeLookup try_get_for_read(const GeometryComponent &component,
-                                       const StringRef attribute_name) const final;
+                                       const AttributeIDRef &attribute_id) const final;
 
   WriteAttributeLookup try_get_for_write(GeometryComponent &component,
-                                         const StringRef attribute_name) const final;
+                                         const AttributeIDRef &attribute_id) const final;
 
-  bool try_delete(GeometryComponent &component, const StringRef attribute_name) const final;
+  bool try_delete(GeometryComponent &component, const AttributeIDRef &attribute_id) const final;
 
   bool try_create(GeometryComponent &component,
-                  const StringRef attribute_name,
+                  const AttributeIDRef &attribute_id,
                   const AttributeDomain domain,
                   const CustomDataType data_type,
                   const AttributeInit &initializer) const final;
@@ -231,10 +232,10 @@ class NamedLegacyCustomDataProvider final : public DynamicAttributesProvider {
   }
 
   ReadAttributeLookup try_get_for_read(const GeometryComponent &component,
-                                       const StringRef attribute_name) const final;
+                                       const AttributeIDRef &attribute_id) const final;
   WriteAttributeLookup try_get_for_write(GeometryComponent &component,
-                                         const StringRef attribute_name) const final;
-  bool try_delete(GeometryComponent &component, const StringRef attribute_name) const final;
+                                         const AttributeIDRef &attribute_id) const final;
+  bool try_delete(GeometryComponent &component, const AttributeIDRef &attribute_id) const final;
   bool foreach_attribute(const GeometryComponent &component,
                          const AttributeForeachCallback callback) const final;
   void foreach_domain(const FunctionRef<void(AttributeDomain)> callback) const final;
diff --git a/source/blender/blenkernel/intern/curve_eval.cc b/source/blender/blenkernel/intern/curve_eval.cc
index 5c18f6f3807..1c4f9c5a6ab 100644
--- a/source/blender/blenkernel/intern/curve_eval.cc
+++ b/source/blender/blenkernel/intern/curve_eval.cc
@@ -25,6 +25,7 @@
 
 #include "DNA_curve_types.h"
 
+#include "BKE_anonymous_attribute.hh"
 #include "BKE_curve.h"
 #include "BKE_spline.hh"
 
@@ -37,6 +38,7 @@ using blender::MutableSpan;
 using blender::Span;
 using blender::StringRefNull;
 using blender::Vector;
+using blender::bke::AttributeIDRef;
 
 blender::Span<SplinePtr> CurveEval::splines() const
 {
@@ -330,13 +332,13 @@ void CurveEval::assert_valid_point_attributes() const
     return;
   }
   const int layer_len = splines_.first()->attributes.data.totlayer;
-  Map<StringRefNull, AttributeMetaData> map;
+  Map<AttributeIDRef, AttributeMetaData> map;
   for (const SplinePtr &spline : splines_) {
     BLI_assert(spline->attributes.data.totlayer == layer_len);
     spline->attributes.foreach_attribute(
-        [&](StringRefNull name, const AttributeMetaData &meta_data) {
+        [&](const AttributeIDRef &attribute_id, const AttributeMetaData &meta_data) {
           map.add_or_modify(
-              name,
+              attribute_id,
               [&](AttributeMetaData *map_data) {
                 /* All unique attribute names should be added on the first spline. */
                 BLI_assert(spline == splines_.first());
diff --git a/source/blender/blenkernel/intern/customdata.c b/source/blender/blenkernel/intern/customdata.c
index 1a3200a9b6c..ad2d5d267d5 100644
--- a/source/blender/blenkernel/intern/customdata.c
+++ b/source/blender/blenkernel/intern/customdata.c
@@ -46,6 +46,7 @@
 
 #include "BLT_translation.h"
 
+#include "BKE_anonymous_attribute.h"
 #include "BKE_customdata.h"
 #include "BKE_customdata_file.h"
 #include "BKE_deform.h"
@@ -2127,6 +2128,11 @@ bool CustomData_merge(const struct CustomData *source,
     if (flag & CD_FLAG_NOCOPY) {
       continue;
     }
+    if (layer->anonymous_id &&
+        !BKE_anonymous_attribute_id_has_strong_references(layer->anonymous_id)) {
+      /* This attribute is not referenced anymore, so it can be treated as if it didn't exist. */
+      continue;
+    }
     if (!(mask & CD_TYPE_AS_MASK(type))) {
       continue;
     }
@@ -2166,6 +2172,11 @@ bool CustomData_merge(const struct CustomData *source,
       newlayer->active_mask = lastmask;
       newlayer->flag |= flag & (CD_FLAG_EXTERNAL | CD_FLAG_IN_MEMORY);
       changed = true;
+
+      if (layer->anonymous_id != NULL) {
+        BKE_anonymous_attribute_id_increment_weak(layer->anonymous_id);
+        newlayer->anonymous_id = layer->anonymous_id;
+      }
     }
   }
 
@@ -2206,6 +2217,10 @@ static void customData_free_layer__internal(CustomDataLayer *layer, int totelem)
 {
   const LayerTypeInfo *typeInfo;
 
+  if (layer->anonymous_id != NULL) {
+    BKE_anonymous_attribute_id_decrement_weak(layer->anonymous_id);
+    layer->anonymous_id = NULL;
+  }
   if (!(layer->flag & CD_FLAG_NOFREE) && layer->data) {
     typeInfo = layerType_getInfo(layer->type);
 
@@ -2649,6 +2664,27 @@ void *CustomData_add_layer_named(CustomData *data,
   return NULL;
 }
 
+void *CustomData_add_layer_anonymous(struct CustomData *data,
+                                     int type,
+                                     eCDAllocType alloctype,
+                                     void *layerdata,
+                                     int totelem,
+                                     const AnonymousAttributeID *anonymous_id)
+{
+  const char *name = BKE_anonymous_attribute_id_internal_name(anonymous_id);
+  CustomDataLayer *layer = customData_add_layer__internal(
+      data, type, alloctype, layerdata, totelem, name);
+  CustomData_update_typemap(data);
+
+  if (layer == NULL) {
+    return NULL;
+  }
+
+  BKE_anonymous_attribute_id_increment_weak(anonymous_id);
+  layer->anonymous_id = anonymous_id;
+  return layer->data;
+}
+
 bool CustomData_free_layer(CustomData *data, int type, int totelem, int index)
 {
   const int index_first = CustomData_get_layer_index(data, type);
@@ -2812,6 +2848,20 @@ void *CustomData_duplicate_referenced_layer_named(CustomData *data,
   return customData_duplicate_referenced_layer_index(data, layer_index, totelem);
 }
 
+void *CustomData_duplicate_referenced_layer_anonymous(CustomData *data,
+                                                      const int UNUSED(type),
+                                                      const AnonymousAttributeID *anonymous_id,
+                                                      const int totelem)
+{
+  for (int i = 0; i < data->totlayer; i++) {
+    if (data->layers[i].anonymous_id == anonymous_id) {
+      return customData_duplicate_referenced_layer_index(data, i, totelem);
+    }
+  }
+  BLI_assert_unreachable();
+  return NULL;
+}
+
 void CustomData_duplicate_referenced_layers(CustomData *data, int totelem)
 {
   for (int i = 0; i < data->totlayer; i++) {
@@ -4244,7 +4294,8 @@ void CustomData_blend_write_prepare(CustomData *data,
 
   for (i = 0, j = 0; i < totlayer; i++) {
     CustomDataLayer *layer = &data->layers[i];
-    if (layer->flag & CD_FLAG_NOCOPY) { /* Layers with this flag set are not written to file. */
+    /* Layers with this flag set are not written to file. */
+    if ((layer->flag & CD_FLAG_NOCOPY) || layer->anonymous_id != NULL) {
       data->totlayer--;
       // CLOG_WARN(&LOG, "skipping layer %p (%s)", layer, layer->name);
     }
diff --git a/source/blender/blenkernel/intern/geometry_component_curve.cc b/source/blender/blenkernel/intern/geometry_component_curve.cc
index 0b6ba966974..a24b60ee288 100644
--- a/source/blender/blenkernel/intern/geometry_component_curve.cc
+++ b/source/blender/blenkernel/intern/geometry_component_curve.cc
@@ -892,7 +892,7 @@ class DynamicPointAttributeProvider final : public DynamicAttributesProvider {
 
  public:
   ReadAttributeLookup try_get_for_read(const GeometryComponent &component,
-                                       const StringRef attribute_name) const final
+                                       const AttributeIDRef &attribute_id) const final
   {
     const CurveEval *curve = get_curve_from_component_for_read(component);
     if (curve == nullptr || curve->splines().size() == 0) {
@@ -902,13 +902,13 @@ class DynamicPointAttributeProvider final : public DynamicAttributesProvider {
     Span<SplinePtr> splines = curve->splines();
     Vector<GSpan> spans; /* GSpan has no default constructor. */
     spans.reserve(splines.size());
-    std::optional<GSpan> first_span = splines[0]->attributes.get_for_read(attribute_name);
+    std::optional<GSpan> first_span = splines[0]->attributes.get_for_read(attribute_id);
     if (!first_span) {
       return {};
     }
     spans.append(*first_span);
     for (const int i : IndexRange(1, splines.size() - 1)) {
-      std::optional<GSpan> span = splines[i]->attributes.get_for_read(attribute_name);
+      std::optional<GSpan> span = splines[i]->attributes.get_for_read(attribute_id);
       if (!span) {
         /* All splines should have the same set of data layers. It would be possible to recover
          * here and return partial data instead, but that would add a lot of complexity for a
@@ -945,7 +945,7 @@ class DynamicPointAttributeProvider final : public DynamicAttributesProvider {
 
   /* This function is almost the same as #try_get_for_read, but without const. */
   WriteAttributeLookup try_get_for_write(GeometryComponent &component,
-                                         const StringRef attribute_name) const final
+                                         const AttributeIDRef &attribute_id) const final
   {
     CurveEval *curve = get_curve_from_component_for_write(component);
     if (curve == nullptr || curve->splines().size() == 0) {
@@ -955,13 +955,13 @@ class DynamicPointAttributeProvider final : public DynamicAttributesProvider {
     MutableSpan<SplinePtr> splines = curve->splines();
     Vector<GMutableSpan> spans; /* GMutableSpan has no default constructor. */
     spans.reserve(splines.size());
-    std::optional<GMutableSpan> first_span = splines[0]->attributes.get_for_write(attribute_name);
+    std::optional<GMutableSpan> first_span = splines[0]->attributes.get_for_write(attribute_id);
     if (!first_span) {
       return {};
     }
     spans.append(*first_span);
     for (const int i : IndexRange(1, splines.size() - 1)) {
-      std::optional<GMutableSpan> span = splines[i]->attributes.get_for_write(attribute_name);
+      std::optional<GMutableSpan> span = splines[i]->attributes.get_for_write(attribute_id);
       if (!span) {
         /* All splines should have the same set of data layers. It would be possible to recover
          * here and return partial data instead, but that would add a lot of complexity for a
@@ -996,7 +996,7 @@ class DynamicPointAttributeProvider final : public DynamicAttributesProvider {
     return attribute;
   }
 
-  bool try_delete(GeometryComponent &component, const StringRef attribute_name) const final
+  bool try_delete(GeometryComponent &component, const AttributeIDRef &attribute_id) const final
   {
     CurveEval *curve = get_curve_from_component_for_write(component);
     if (curve == nullptr) {
@@ -1006,7 +1006,7 @@ class DynamicPointAttributeProvider final : public DynamicAttributesProvider {
     /* Reuse the boolean for all splines; we expect all splines to have the same attributes. */
     bool layer_freed = false;
     for (SplinePtr &spline : curve->splines()) {
-      layer_freed = spline->attributes.remove(attribute_name);
+      layer_freed = spline->attributes.remove(attribute_id);
     }
     return layer_freed;
   }
@@ -1034,7 +1034,7 @@ class DynamicPointAttributeProvider final : public DynamicAttributesProvider {
   }
 
   bool try_create(GeometryComponent &component,
-                  const StringRef attribute_name,
+                  const AttributeIDRef &attribute_id,
                   const AttributeDomain domain,
                   const CustomDataType data_type,
                   const AttributeInit &initializer) const final
@@ -1053,7 +1053,7 @@ class DynamicPointAttributeProvider final : public DynamicAttributesProvider {
     /* First check the one case that allows us to avoid copying the input data. */
     if (splines.size() == 1 && initializer.type == AttributeInit::Type::MoveArray) {
       void *source_data = static_cast<const AttributeInitMove &>(initializer).data;
-      if (!splines[0]->attributes.create_by_move(attribute_name, data_type, source_data)) {
+      if (!splines[0]->attributes.create_by_move(attribute_id, data_type, source_data)) {
         MEM_freeN(source_data);
         return false;
       }
@@ -1062,7 +1062,7 @@ class DynamicPointAttributeProvider final : public DynamicAttributesProvider {
 
     /* Otherwise just create a custom data layer on each of the splines. */
     for (const int i : splines.index_range()) {
-      if (!splines[i]->attributes.create(attribute_name, data_type)) {
+      if (!splines[i]->attributes.create(attribute_id, data_type)) {
         /* If attribute creation fails on one of the splines, we cannot leave the custom data
          * layers in the previous splines around, so delete them before returning. However,
          * this is not an expected case. */
@@ -1076,7 +1076,7 @@ class DynamicPointAttributeProvider final : public DynamicAttributesProvider {
       return true;
     }
 
-    WriteAttributeLookup write_attribute = this->try_get_for_write(component, attribute_name);
+    WriteAttributeLookup write_attribute = this->try_get_for_write(component, attribute_id);
     /* We just created the attribute, it should exist. */
     BLI_assert(write_attribute);
 
diff --git a/source/blender/blenkernel/intern/geometry_component_mesh.cc b/source/blender/blenkernel/intern/geometry_component_mesh.cc
index ef93a3f9b3f..9a4b8f4eb92 100644
--- a/source/blender/blenkernel/intern/geometry_component_mesh.cc
+++ b/source/blender/blenkernel/intern/geometry_component_mesh.cc
@@ -818,16 +818,20 @@ class VArray_For_VertexWeights final : public VArray<float> {
 class VertexGroupsAttributeProvider final : public DynamicAttributesProvider {
  public:
   ReadAttributeLookup try_get_for_read(const GeometryComponent &component,
-                                       const StringRef attribute_name) const final
+                                       const AttributeIDRef &attribute_id) const final
   {
     BLI_assert(component.type() == GEO_COMPONENT_TYPE_MESH);
+    if (!attribute_id.is_named()) {
+      return {};
+    }
     const MeshComponent &mesh_component = static_cast<const MeshComponent &>(component);
     const Mesh *mesh = mesh_component.get_for_read();
     if (mesh == nullptr) {
       return {};
     }
+    const std::string name = attribute_id.name();
     const int vertex_group_index = BLI_findstringindex(
-        &mesh->vertex_group_names, attribute_name.data(), offsetof(bDeformGroup, name));
+        &mesh->vertex_group_names, name.c_str(), offsetof(bDeformGroup, name));
     if (vertex_group_index < 0) {
       return {};
     }
@@ -843,17 +847,21 @@ class VertexGroupsAttributeProvider final : public DynamicAttributesProvider {
   }
 
   WriteAttributeLookup try_get_for_write(GeometryComponent &component,
-                                         const StringRef attribute_name) const final
+                                         const AttributeIDRef &attribute_id) const final
   {
     BLI_assert(component.type() == GEO_COMPONENT_TYPE_MESH);
+    if (!attribute_id.is_named()) {
+      return {};
+    }
     MeshComponent &mesh_component = static_cast<MeshComponent &>(component);
     Mesh *mesh = mesh_component.get_for_write();
     if (mesh == nullptr) {
       return {};
     }
 
+    const std::string name = attribute_id.name();
     const int vertex_group_index = BLI_findstringindex(
-        &mesh->vertex_group_names, attribute_name.data(), offsetof(bDeformGroup, name));
+        &mesh->vertex_group_names, name.c_str(), offsetof(bDeformGroup, name));
     if (vertex_group_index < 0) {
       return {};
     }
@@ -872,17 +880,21 @@ class VertexGroupsAttributeProvider final : public DynamicAttributesProvider {
         ATTR_DOMAIN_POINT};
   }
 
-  bool try_delete(GeometryComponent &component, const StringRef attribute_name) const final
+  bool try_delete(GeometryComponent &component, const AttributeIDRef &attribute_id) const final
   {
     BLI_assert(component.type() == GEO_COMPONENT_TYPE_MESH);
+    if (!attribute_id.is_named()) {
+      return false;
+    }
     MeshComponent &mesh_component = static_cast<MeshComponent &>(component);
     Mesh *mesh = mesh_component.get_for_write();
     if (mesh == nullptr) {
       return true;
     }
 
+    const std::string name = attribute_id.name();
     const int vertex_group_index = BLI_findstringindex(
-        &mesh->vertex_group_names, attribute_name.data(), offsetof(bDeformGroup, name));
+        &mesh->vertex_group_names, name.c_str(), offsetof(bDeformGroup, name));
     if (vertex_group_index < 0) {
       return false;
     }
diff --git a/source/blender/blenkernel/intern/geometry_set_instances.cc b/source/blender/blenkernel/intern/geometry_set_instances.cc
index 376792b9b96..0e19324a3c1 100644
--- a/source/blender/blenkernel/intern/geometry_set_instances.cc
+++ b/source/blender/blenkernel/intern/geometry_set_instances.cc
@@ -331,7 +331,7 @@ void geometry_set_instances_attribute_foreach(const GeometrySet &geometry_set,
 void geometry_set_gather_instances_attribute_info(Span<GeometryInstanceGroup> set_groups,
                                                   Span<GeometryComponentType> component_types,
                                                   const Set<std::string> &ignored_attributes,
-                                                  Map<std::string, AttributeKind> &r_attributes)
+                                                  Map<AttributeIDRef, AttributeKind> &r_attributes)
 {
   for (const GeometryInstanceGroup &set_group : set_groups) {
     const GeometrySet &set = set_group.geometry_set;
@@ -341,23 +341,24 @@ void geometry_set_gather_instances_attribute_info(Span<GeometryInstanceGroup> se
       }
       const GeometryComponent &component = *set.get_component_for_read(component_type);
 
-      component.attribute_foreach([&](StringRefNull name, const AttributeMetaData &meta_data) {
-        if (ignored_attributes.contains(name)) {
-          return true;
-        }
-        auto add_info = [&](AttributeKind *attribute_kind) {
-          attribute_kind->domain = meta_data.domain;
-          attribute_kind->data_type = meta_data.data_type;
-        };
-        auto modify_info = [&](AttributeKind *attribute_kind) {
-          attribute_kind->domain = meta_data.domain; /* TODO: Use highest priority domain. */
-          attribute_kind->data_type = bke::attribute_data_type_highest_complexity(
-              {attribute_kind->data_type, meta_data.data_type});
-        };
-
-        r_attributes.add_or_modify(name, add_info, modify_info);
-        return true;
-      });
+      component.attribute_foreach(
+          [&](const AttributeIDRef &attribute_id, const AttributeMetaData &meta_data) {
+            if (attribute_id.is_named() && ignored_attributes.contains(attribute_id.name())) {
+              return true;
+            }
+            auto add_info = [&](AttributeKind *attribute_kind) {
+              attribute_kind->domain = meta_data.domain;
+              attribute_kind->data_type = meta_data.data_type;
+            };
+            auto modify_info = [&](AttributeKind *attribute_kind) {
+              attribute_kind->domain = meta_data.domain; /* TODO: Use highest priority domain. */
+              attribute_kind->data_type = bke::attribute_data_type_highest_complexity(
+                  {attribute_kind->data_type, meta_data.data_type});
+            };
+
+            r_attributes.add_or_modify(attribute_id, add_info, modify_info);
+            return true;
+          });
     }
   }
 }
@@ -512,11 +513,11 @@ static Mesh *join_mesh_topology_and_builtin_attributes(Span<GeometryInstanceGrou
 
 static void join_attributes(Span<GeometryInstanceGroup> set_groups,
                             Span<GeometryComponentType> component_types,
-                            const Map<std::string, AttributeKind> &attribute_info,
+                            const Map<AttributeIDRef, AttributeKind> &attribute_info,
                             GeometryComponent &result)
 {
-  for (Map<std::string, AttributeKind>::Item entry : attribute_info.items()) {
-    StringRef name = entry.key;
+  for (Map<AttributeIDRef, AttributeKind>::Item entry : attribute_info.items()) {
+    const AttributeIDRef attribute_id = entry.key;
     const AttributeDomain domain_output = entry.value.domain;
     const CustomDataType data_type_output = entry.value.data_type;
     const CPPType *cpp_type = bke::custom_data_type_to_cpp_type(data_type_output);
@@ -524,7 +525,7 @@ static void join_attributes(Span<GeometryInstanceGroup> set_groups,
 
     result.attribute_try_create(
         entry.key, domain_output, data_type_output, AttributeInitDefault());
-    WriteAttributeLookup write_attribute = result.attribute_try_get_for_write(name);
+    WriteAttributeLookup write_attribute = result.attribute_try_get_for_write(attribute_id);
     if (!write_attribute || &write_attribute.varray->type() != cpp_type ||
         write_attribute.domain != domain_output) {
       continue;
@@ -543,7 +544,7 @@ static void join_attributes(Span<GeometryInstanceGroup> set_groups,
             continue; /* Domain size is 0, so no need to increment the offset. */
           }
           GVArrayPtr source_attribute = component.attribute_try_get_for_read(
-              name, domain_output, data_type_output);
+              attribute_id, domain_output, data_type_output);
 
           if (source_attribute) {
             fn::GVArray_GSpan src_span{*source_attribute};
@@ -653,7 +654,7 @@ static void join_instance_groups_mesh(Span<GeometryInstanceGroup> set_groups,
   }
 
   /* Don't copy attributes that are stored directly in the mesh data structs. */
-  Map<std::string, AttributeKind> attributes;
+  Map<AttributeIDRef, AttributeKind> attributes;
   geometry_set_gather_instances_attribute_info(
       set_groups,
       component_types,
@@ -674,7 +675,7 @@ static void join_instance_groups_pointcloud(Span<GeometryInstanceGroup> set_grou
   PointCloudComponent &dst_component = result.get_component_for_write<PointCloudComponent>();
   dst_component.replace(new_pointcloud);
 
-  Map<std::string, AttributeKind> attributes;
+  Map<AttributeIDRef, AttributeKind> attributes;
   geometry_set_gather_instances_attribute_info(
       set_groups, {GEO_COMPONENT_TYPE_POINT_CLOUD}, {"position"}, attributes);
   join_attributes(set_groups,
@@ -708,7 +709,7 @@ static void join_instance_groups_curve(Span<GeometryInstanceGroup> set_groups, G
   CurveComponent &dst_component = result.get_component_for_write<CurveComponent>();
   dst_component.replace(curve);
 
-  Map<std::string, AttributeKind> attributes;
+  Map<AttributeIDRef, AttributeKind> attributes;
   geometry_set_gather_instances_attribute_info(
       set_groups,
       {GEO_COMPONENT_TYPE_CURVE},
diff --git a/source/blender/blenkernel/intern/node.cc b/source/blender/blenkernel/intern/node.cc
index be4fd7aac4f..950026b9d65 100644
--- a/source/blender/blenkernel/intern/node.cc
+++ b/source/blender/blenkernel/intern/node.cc
@@ -5140,6 +5140,7 @@ static void registerGeometryNodes()
   register_node_type_geo_attribute_convert();
   register_node_type_geo_attribute_curve_map();
   register_node_type_geo_attribute_fill();
+  register_node_type_geo_attribute_capture();
   register_node_type_geo_attribute_map_range();
   register_node_type_geo_attribute_math();
   register_node_type_geo_attribute_mix();
@@ -5174,7 +5175,10 @@ static void registerGeometryNodes()
   register_node_type_geo_curve_trim();
   register_node_type_geo_delete_geometry();
   register_node_type_geo_edge_split();
+  register_node_type_geo_input_index();
   register_node_type_geo_input_material();
+  register_node_type_geo_input_normal();
+  register_node_type_geo_input_position();
   register_node_type_geo_is_viewport();
   register_node_type_geo_join_geometry();
   register_node_type_geo_material_assign();
@@ -5202,6 +5206,7 @@ static void registerGeometryNodes()
   register_node_type_geo_select_by_handle_type();
   register_node_type_geo_select_by_material();
   register_node_type_geo_separate_components();
+  register_node_type_geo_set_position();
   register_node_type_geo_subdivision_surface();
   register_node_type_geo_switch();
   register_node_type_geo_transform();